Abstract Opioid overdose rates have increased dramatically since 2000 with prescription opioids acting as the primary driver of this trend for most of this time period. In more recent years, heroin and illicit synthetic opioids have increased rapidly as well. In response to these trends, numerous federal and state policies have been adopted to curb the overdose rate. These policies frequently attempt to limit the supply of prescription opioids available for nonmedical use. Specific features of prescription drug monitoring programs (PDMPs) have been found effective. In this project, we will study the effectiveness of electronic prescribing (e-prescribing) mandates on opioid abuse outcomes. E-prescribing combines many of the features of PDMPs which researchers believe are especially successful in reducing opioid abuse, suggesting substantial scope for curbing the rise in overdoses. This project will provide some of the first evidence about the potential effectiveness of these mandates. E-prescribing has become increasingly prevalent in the United States, including a 256% increase between 2015 and 2016 in the number of controlled substances prescribed electronically. New York experienced especially sharp growth in e-prescribing rates due to the introduction of an e-prescribing mandate in March 2016. Maine implemented a mandate for controlled substances only, beginning in July 2017. While not enforced, a Minnesota mandate has been technically effective since 2011 and has increased e-prescribing rates. In this project, we will study the ramifications of the New York and Maine mandates on a comprehensive set of opioid- related outcomes while also considering whether the Minnesota law may have had similar effects by encouraging use of e-prescribing. In all cases, we will study each state separately given the major differences across the state policies, using empirical methods appropriate for case studies. We will collect and study a wide range of policy-relevant measures. We will use claims data on prescription drugs to construct measures that have been shown to predict doctor shopping, overprescribing, and abuse. We will also study total opioid supply in a state. We will also examine whether the mandates reduce opioid-related emergency department visits and inpatient stays as well as study the effects of the mandates on opioid-related mortality rates. Because research has found that limiting access to prescription opioids for non-medical use may lead to increases in heroin and fentanyl abuse, we will pay special attention to whether there are compensating effects in overdoses rates involving heroin or synthetic opioids.